Cam and valvetrain longevity....??? low duration high lift...
#882
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My controlled induction 2016 cam software, suggests for Tim's engine, max rpm of 6000, A 252/260 108 LSA 654/680 lift cam.
My dyno simulator, with tims 241/246, 112 LSA cam, shows a peak HP of 658HP at, 5500 with his components( prob not far off if tim had dynoed with no accessories and dyno headers). Switching to the cam softwares 252/260, hp peak goes up to 699 at 6000RPM. Switching that 252/260, from a 108 LSA, to a 112 LSA with a 110ICL, the HP climbs again, to 711hp at 6000. Going to a 114, with a 110 ICL, drops it big time, to 683HP at 6000rpm.
So, back to the 252/260, 112 LSA setup. Sim say 711HP at 6000RPM. Thats with a CFM rating of 1000CFM. Bumping that, to a 1250 CFM, the engine is now making 728HP at 6000RPM. Peak torque, still in the 4500RPM range.
Now, granted thats just pplaying around with a software program, but that certainly seems fairly in line with this guys claims?
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked. Also built similar engines, but made them 509's, using the stock crank, they would make about 680hp and about 665 for tq, but, I would pull the duration back to 248-256,to keep the same rpm range.They would actualy go 6000-6200 for peak hp, same lobe family, so the lift was the same, and the same 112 lobe sep.
My dyno simulator, with tims 241/246, 112 LSA cam, shows a peak HP of 658HP at, 5500 with his components( prob not far off if tim had dynoed with no accessories and dyno headers). Switching to the cam softwares 252/260, hp peak goes up to 699 at 6000RPM. Switching that 252/260, from a 108 LSA, to a 112 LSA with a 110ICL, the HP climbs again, to 711hp at 6000. Going to a 114, with a 110 ICL, drops it big time, to 683HP at 6000rpm.
So, back to the 252/260, 112 LSA setup. Sim say 711HP at 6000RPM. Thats with a CFM rating of 1000CFM. Bumping that, to a 1250 CFM, the engine is now making 728HP at 6000RPM. Peak torque, still in the 4500RPM range.
Now, granted thats just pplaying around with a software program, but that certainly seems fairly in line with this guys claims?
Here is a few that I have built for power boats. 540-548 bbc's, ported Iron eagle 308 heads, not radical porting, but detail work, chamber work, ex port work, the intake received attention thru the whole runner, about 320cc ish when done. 10:1, the Dart single plane that came on the boat originaly, on the mecruiser HP 500 502, Custom comp hydraulic roller, 252-260 at .050, .640 lift, 112 lobe sep. For numerous reasons. Did like 8-10 of those, either 540's or 548's out of the original 502 blocks. THey would make 715-730 hp, and about the same for tq, peaked about 5800 for hp, in the 4500ish for tq, depending on carbs used. And they rocked. Also built similar engines, but made them 509's, using the stock crank, they would make about 680hp and about 665 for tq, but, I would pull the duration back to 248-256,to keep the same rpm range.They would actualy go 6000-6200 for peak hp, same lobe family, so the lift was the same, and the same 112 lobe sep.
Last edited by articfriends; 10-01-2016 at 07:27 PM.
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#883
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My heads and intakes will be touched up, port marched and flowed before I even think about cams, that's per my buddy that's helping me get this fixed up, I am gonna ask him if bumping compression from 9.5 to 9.8 will hurt anything, I run 93 no matter what also so that's not a concern for me... But that's where I am starting, I am gonna look at everyone's ideas but minimalist who actually influences me, as of now it's my buddy Bill, scott and Joe...
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#884
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My heads and intakes will be touched up, port marched and flowed before I even think about cams, that's per my buddy that's helping me get this fixed up, I am gonna ask him if bumping compression from 9.5 to 9.8 will hurt anything, I run 93 no matter what also so that's not a concern for me... But that's where I am starting, I am gonna look at everyone's ideas but minimalist who actually influences me, as of now it's my buddy Bill, scott and Joe...
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#885
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That is almost dead identical to my blower cam from MK I previously ran that am going to reuse as a start ( may very well have to up compression or change cam specs before im done) to my 540 n/a project with except its on a 114, shows like 708 theoretical hp with a little less compression, prob too much cam for compression I have but am going to run it anyways, Smitty
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#889
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Tim, it would be nice if the guy doing your head+intake could flow your heads. Then flow heads with the intake then with intake & carb. You would probably learn something...
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